As technology improves, electronic devices, such as cellular telephones, personal digital assistants (PDAs), pagers, and the like, appear to get smaller and smaller. With this decrease in size almost necessarily comes a decrease in the size of the display screens of those devices. At the same time, another advance in technology has been the use of these display screens as input devices for their corresponding electronic device. The display screens of many electronic devices are touch sensitive input devices, or touchscreens. However, because the display screens appear to be getting smaller over time, use of the display screen as a touch sensitive input device has become somewhat difficult. This is particularly true where it is intended that an individual use his or her finger to select a selectable item displayed on the touchscreen. As a user places his or her finger on a small item displayed on the touchscreen, the finger will likely occlude the item completely, as well as overlap some of the adjacent items displayed. Consequently, it is difficult if not impossible for the user to be certain which item he or she is selecting.
Several solutions have been proposed for facilitating data entry into relatively small touch sensitive input devices, or touchscreens. Each of these solutions, however, has at least one drawback. One solution is to dynamically magnify a selectable item on the touchscreen when the cursor, or other means of selecting the item, is within a certain proximity to the selectable item. According to this solution, a window displaying a magnified version of a selectable item opens directly on top of the selectable item when the cursor comes within proximity to the selectable item. As the cursor moves closer to the selectable item, the window size and magnification of the selectable item increase until the cursor reaches the magnified window. One drawback of this solution is that it may be difficult to implement where selectable items were scattered throughout a touchscreen, rather than in a single row or column. In particular, where the item the user wishes to select is surrounded by other selectable items, as the cursor moves closer to the intended item, one of the surrounding items would likely become magnified, thereby potentially making it difficult, if not impossible, to see and select the intended item.
Another solution, which may solve the above drawback to the first solution, is to only open the window displaying the magnified version of the selectable item when the user actuates a button. This solution, however, requires additional steps and may further make operating the electronic device to input data a two-handed operation, which is less than ideal. A third solution that has been proposed is to continuously display a window including a magnified view of what is under the window. In this solution, the window has edges that may not be well defined, wherein the magnification decreases smoothly at the margins of the window. According to this solution, however, the magnified window moves with the cursor and may cause the magnified view to appear unstable, restless and wobbly. This solution, therefore, would not facilitate data entry into the touchscreen.
In addition to the foregoing, each of the above solutions may have a further drawback in that the window displaying a magnified version of the selectable item appears directly on top of the selectable item. Where, for example, an individual is using his or her finger, and most commonly his or her thumb (e.g., where the individual is operating the electronic device with one hand) to select the item on the touchscreen, the magnification, and consequently the window, would have to be fairly large in order to make the selected item viewable from under the individual's finger. Given the above-referenced limited size of the display screen, having a large magnification window may be undesirable and may in fact be unfeasible in some circumstances. In addition, even if the magnification window is large enough to be viewable underneath the individual's finger, at least part of the selectable item may still be occluded at all times.
Further proposed solutions for facilitating data entry into relatively small touch sensitive input devices, or touchscreens that address the above drawback are to offset a magnified or unmagnified window above, below, to the left or to the right of the selectable item. Where magnified, this solution, as well as the above solutions, may have the additional drawback that magnifying parts of a graphical user interface generally requires vector graphics, which are not always available on electronic devices, such as cellular telephones; thus potentially causing these solutions to not be possible in some instances.
In addition, if the contents of the original view are magnified in the window, the amplitude of finger movements, including tremor, may be magnified as well. For example, if the contents of the window are magnified to twice their size (i.e., 2× magnification), any finger movement may cause the window contents to move with twice the speed. This may make the view in the window appear restless and hard to control. This problem could be solved by retaining the “gain” of movement (i.e., window content movement/finger movement) as a one-to-one ratio even if the view magnification is two-to-one. Unfortunately, this may create a new problem when the user needs to select (i.e., “paint”) a string of characters. In particular, in this situation, by the time the finger reaches the end of the string, the window and the pointer may only be halfway along the string. In other words, the finger and the pointer may no longer be pointing at the same item.
In addition, use of an offset window may have further drawbacks, whether the contents are magnified or not. In particular, as noted above, the size of the touchscreen may be rather small. As a result, there may not be sufficient room on the touchscreen to display an additional window in which items are displayed large enough to provide an improvement over the original display. In addition, the contents of the original touchscreen display are not obscured not only by the user's finger, but also the offset window. As you increase the size of the offset window to further facilitate data entry, the more you obscure the original touchscreen display.
Yet another solution proposed has been to provide a set of crosshairs just above the position where the user places his or her finger, which the user can use to aim. Several drawbacks may exist for this solution as well. In particular, one drawback may be that it forces the user to guess to some extent where to place his or her finger in order to select a certain item on the touchscreen, since he or she can no longer simply touch the screen at the location of that item. In addition, it may be very difficult to place a cursor or select an item at a location near one of the edges of the touchscreen.
A need, therefore, exists for a technique for facilitating data entry into a relatively small touch sensitive input device or touchscreen that overcomes at least the above-described drawbacks.